This invention relates generally to the art of magnetic sputtering, and more particularly to the art of anode designs for magnetic sputtering.
U.S. Pat. No. 4,166,018 to Chapin describes a sputtering apparatus in which a magnetic field is formed adjacent a planar sputtering surface, the field comprising arching lines of flux over a closed loop erosion region on the sputtering surface. Chapin teaches that the configuration of the anode is relatively unimportant, but it is preferred that the anode be of relatively small size compared to the cathode surface. In the illustrated embodiment, the anode comprises a bar of relatively small cross-section which extends around the cathode spaced from its perimeter.
In prior art literature on magnetic sputtering, the design of the anode system is typically either ignored or dismissed as relatively unimportant. However, it is diclosed in U.S. Pat. No. 4,478,702 to Gillery et al that appropriate anode design is essential to attaining very uniform sputtered films, particularly in reactive sputtering processes, and most especially when depositing insulating layers, such as titanium oxide.